How do I implement Google Sign-In for @cisstudent.no and @cisteacher.no domains on my web project with PHP, Javascript, and CSS?

Im making a website in my design class, and I need to add a log in so that only specific google domains to our school can view the pages I make and not the rest of the world.

It would need to be google log in where the domains @cisstudent.no and @cisteacher.no are the ones who access the pages. I am using PHP, Javascript and CSS from beforehand. is anyone willing to help me?